Posted by **ramana** on Wednesday, June 18, 2008 at 3:36pm.

what rate willl an amount double itself in 20 years at simple interest?

- 10th -
**DrBob222**, Wednesday, June 18, 2008 at 3:59pm
(1.00+x)^20 = 2 where x is the percent. If we call 1.00 + x = Y, then

(Y)^20 = 2

20*log(Y) = log 2

20*log(Y) = 0.30103

log Y = 0.30103/2 =

Solve for y and that will tell you what 1+interest rate must be. Subtracting 1.00 will give you the interest rate. I get something like 3.5%

- 10th -
**Damon**, Wednesday, June 18, 2008 at 4:04pm
In 20 years you must make one times the original amount in interest.

20 x = 1

x = .05 or 5%

- 10th -
**Damon**, Wednesday, June 18, 2008 at 4:05pm
It said simple, not compound.

## Answer this Question

## Related Questions

- math (SIMPLE INTEREST) - 4.the amount in an account which was opened 180 days ...
- math (SIMPLE INTEREST) - at what rate of simple interest will a sum of money ...
- compound interest - How do I solve these problems? Complete the table for a ...
- math - Amount of an investment. The amount of an investment of P dollars for t ...
- maths - A sum of money becomes 8/5 of itself in 5 years at certain rate of ...
- Math - The amount of an investment of P dollars for t years at simple interest ...
- Math - Your Aunt will give your $1,ooo if you invest it for 10 years in an ...
- Math - 1. Find the total amount if you deposit $500 at a rate of 5% for two ...
- math,algebra - Is this correct Business and finance. The simples interest I on a...
- maths - The difference of compound interest and simple interest on an amount at ...